Test quoting of shebang lines.

See issues #188 and #398; on Windows, the launcher executables support shebangs
that use quotes to escape spaces, so these should be used when necessary. On
the other hand, Unix systems don't support shebangs with quotes so they should
never have quotes.

setuptools/tests/test_install_scripts.py

+"""install_scripts tests
+"""
+
+import io
+import sys
+
+import pytest
+
+from setuptools.command.install_scripts import install_scripts
+from setuptools.dist import Distribution
+from . import contexts
+
+
+class TestInstallScripts:
+    settings = dict(
+        name='foo',
+        entry_points={'console_scripts': ['foo=foo:foo']},
+        version='0.0',
+    )
+    unix_exe = '/usr/dummy-test-path/local/bin/python'
+    unix_spaces_exe = '/usr/bin/env dummy-test-python'
+    win32_exe = 'C:\\Dummy Test Path\\Program Files\\Python 3.3\\python.exe'
+
+    def _run_install_scripts(self, install_dir, executable=None):
+        dist = Distribution(self.settings)
+        dist.script_name = 'setup.py'
+        cmd = install_scripts(dist)
+        cmd.install_dir = install_dir
+        if executable is not None:
+            bs = cmd.get_finalized_command('build_scripts')
+            bs.executable = executable
+        cmd.ensure_finalized()
+        with contexts.quiet():
+            cmd.run()
+
+    @pytest.mark.skipif(sys.platform == 'win32', reason='non-Windows only')
+    def test_sys_executable_escaping_unix(self, tmpdir, monkeypatch):
+        """
+        Ensure that shebang is not quoted on Unix when getting the Python exe
+        from sys.executable.
+        """
+        expected = '#!%s\n' % self.unix_exe
+        monkeypatch.setattr('sys.executable', self.unix_exe)
+        with tmpdir.as_cwd():
+            self._run_install_scripts(str(tmpdir))
+            with io.open(str(tmpdir.join('foo')), 'r') as f:
+                actual = f.readline()
+        assert actual == expected
+
+    @pytest.mark.skipif(sys.platform != 'win32', reason='Windows only')
+    def test_sys_executable_escaping_win32(self, tmpdir, monkeypatch):
+        """
+        Ensure that shebang is quoted on Windows when getting the Python exe
+        from sys.executable and it contains a space.
+        """
+        expected = '#!"%s"\n' % self.win32_exe
+        monkeypatch.setattr('sys.executable', self.win32_exe)
+        with tmpdir.as_cwd():
+            self._run_install_scripts(str(tmpdir))
+            with io.open(str(tmpdir.join('foo-script.py')), 'r') as f:
+                actual = f.readline()
+        assert actual == expected
+
+    @pytest.mark.skipif(sys.platform == 'win32', reason='non-Windows only')
+    def test_executable_with_spaces_escaping_unix(self, tmpdir):
+        """
+        Ensure that shebang on Unix is not quoted, even when a value with spaces
+        is specified using --executable.
+        """
+        expected = '#!%s\n' % self.unix_spaces_exe
+        with tmpdir.as_cwd():
+            self._run_install_scripts(str(tmpdir), self.unix_spaces_exe)
+            with io.open(str(tmpdir.join('foo')), 'r') as f:
+                actual = f.readline()
+        assert actual == expected
+
+    @pytest.mark.skipif(sys.platform != 'win32', reason='Windows only')
+    def test_executable_arg_escaping_win32(self, tmpdir):
+        """
+        Ensure that shebang on Windows is quoted when getting a path with spaces
+        from --executable, that is itself properly quoted.
+        """
+        expected = '#!"%s"\n' % self.win32_exe
+        with tmpdir.as_cwd():
+            self._run_install_scripts(str(tmpdir), '"' + self.win32_exe + '"')
+            with io.open(str(tmpdir.join('foo-script.py')), 'r') as f:
+                actual = f.readline()
+        assert actual == expected